For more on the appointment of the special counsel to investigate Russia's involvement in the 2016 campaign, we're joined now by NPR national political correspondent Mara Liasson. And Mara, we've been talking all evening about who Robert Mueller is. I want you to talk about the role of the man responsible for appointing Robert Mueller to this role, Rod Rosenstein.

MARA LIASSON, BYLINE: Well, Rod Rosenstein really rose to the occasion. You know, just a couple of days ago, Donald Trump had used Rosenstein almost as a human shield when he fired James Comey and, at least in the initial hours, blamed it all on - blamed - gave Rod Rosenstein the credit, said he wrote the recommendation; this is why I fired him. Later, the president contradicted that storyline and said, I would have fired Comey anyway.

But what Rosenstein did in one fell swoop is he caused bipartisanship to break out briefly in Washington, D.C., which is extraordinary.

SHAPIRO: Praising the appointment of Mueller.

LIASSON: He repaired his own credibility and his own reputation which was on the line. Don't forget; he's about to go up to Congress and be questioned about this. This is going to make his life a lot easier the day he goes up there. And he made people who care about the rule of law sigh a sigh of relief because now this investigation has a lot more credibility than it did yesterday.

SHAPIRO: Now, the president put out a statement tonight saying he's confident that an investigation will show there was no collusion and wrongdoing. You have covered enough of these special counsel investigations in the past to know how they go. What can we expect?

LIASSON: First of all, it's going to take a long time. So there's really a lot of good news and bad news here for the White House. On the one hand, if this investigation ends up exonerating Donald Trump and his campaign, it will have a lot of credibility. That's a good thing. Mueller is known as someone who doesn't leak and keeps a low profile and runs a tight ship. That's good for the White House. But he's also known as somebody who's extremely thorough. And these investigations, in my experience, tend to take a very long time. So Donald Trump said in his statement he's hoping that it comes to a quick conclusion. That probably will not be the case.

SHAPIRO: And at the same time, there will be a public investigation unfolding by the House and Senate committees...

LIASSON: Right.

SHAPIRO: ...That are already investigating this.

LIASSON: Right. Those will continue. And he hasn't complained that much. Don't forget; they aren't criminal investigations. They're looking into the entire issue of Russian interference in the campaign. What he has been complaining about as a taxpayer-funded hoax and a waste of time and a false, fake story is this, the FBI investigating.

SHAPIRO: Mueller is also very close with James Comey, the FBI...

LIASSON: Yes, yes.

SHAPIRO: ...Director who was fired last week.

LIASSON: No doubt.

SHAPIRO: That doesn't sound good for Trump.

LIASSON: No, but I think Mueller's considered to be somebody who is very, very fair. Now, don't forget; we are setting up a kind of he-said, he-said situation where Comey has written this memo that's been reported on saying that Donald Trump asked him to go easy on Flynn, see if you can let this investigation go. The White House has said, no, that's totally false; it didn't happen. So in that situation, Mueller is going to be one of the people deciding who has more credibility, Comey or Trump.